Class AcDbLayerIndex

Layer index object used with the AutoCAD index/filter scheme.

An AcDbLayerIndex is an index implementation specialized for layers. It is typically associated with a block table record and used together with AcDbLayerFilter when regenerating xrefs and blocks under the INDEXCTL system variable.

Remarks

Mirrors the ObjectARX AcDbLayerIndex class. In DXF this object is written as type LAYER_INDEX with subclass markers AcDbIndex and AcDbLayerIndex.

See

https://help.autodesk.com/view/OARX/2024/ENU/?guid=OARX-RefGuide-AcDbLayerIndex

Example

const index = new AcDbLayerIndex();
index.lastUpdatedAt = 2451545.0;
index.layerNames = ['0', 'Walls'];
index.idBufferIds = ['1A', '1B'];
index.idBufferEntryCounts = [10, 4];

Hierarchy (View Summary)

Constructors

constructor

Accessors

attrs database entries extensionDictionary idBufferEntryCounts idBufferIds isTemp isUptoDate lastUpdatedAt lastUpdatedAtU layerNames objectId ownerId

Methods

assignDatabase clone clonePreservingIdentity close compute createExtensionDictionary dxfIn dxfInControlString dxfInFields dxfInXData dxfOut dxfOutFields dxfOutXData getAttr getAttrWithoutException getXData newIterator objectBeingIndexedId rebuildFull rebuildModified removeXData restoreFrom setAttr setObjectBeingIndexedId setXData

Constructors

constructor

Accessors

attrs

database

  • get database(): AcDbDatabase

  • Gets the database in which this object is resident.

    When an object isn't added to a database, this property returns the current working database. After it is added to a database, it will be set automatically. You should never set this value manually.

    Returns AcDbDatabase

    The database this object belongs to

    Example

    const db = obj.database;
  • set database(db: AcDbDatabase): void

  • Sets the database for this object.

    This is typically set automatically when the object is added to a database. Manual setting should be avoided unless you know what you're doing.

    Parameters

    Returns void

    Example

    obj.database = myDatabase;

entries

extensionDictionary

  • get extensionDictionary(): undefined | string

  • Gets the objectId of the extension dictionary owned by this object.

    If the object does not have an extension dictionary, this returns undefined.

    In ObjectARX terms, this is equivalent to AcDbObject::extensionDictionary().

    Returns undefined | string

    The extension dictionary objectId, or undefined

    Example

    const dictId = obj.extensionDictionary
    if (dictId) {
      console.log('Has extension dictionary:', dictId)
    }
  • set extensionDictionary(value: undefined | string): void

  • Sets the objectId of the extension dictionary owned by this object.

    This does not create or delete the dictionary object itself ??it only establishes or clears the ownership relationship.

    Passing undefined removes the association.

    Parameters

    • value: undefined | string

      The extension dictionary objectId, or undefined

    Returns void

    Example

    obj.extensionDictionary = dict.objectId

idBufferEntryCounts

idBufferIds

isTemp

  • get isTemp(): any

  • Returns true if this object is temporary and not yet committed to the database.

    A temporary object is identified by its objectId starting with the TEMP prefix.

    Returns any

isUptoDate

  • get isUptoDate(): boolean

  • Returns whether this index is considered up to date.

    Returns boolean

    true if the index is current; otherwise false.

  • set isUptoDate(value: boolean): void

  • Sets whether this index is considered up to date.

    Parameters

    • value: boolean

      true if the index is current.

    Returns void

lastUpdatedAt

  • get lastUpdatedAt(): number

  • Gets the local last-updated timestamp for this index.

    Returns number

    The last-updated timestamp.

    Remarks

    In ObjectARX this returns an AcDbDate. This port stores a numeric timestamp (Julian date when read from DXF group code 40).

  • set lastUpdatedAt(value: number): void

  • Sets the local last-updated timestamp for this index.

    Parameters

    • value: number

      The new timestamp value.

    Returns void

lastUpdatedAtU

  • get lastUpdatedAtU(): number

  • Gets the UTC last-updated timestamp for this index.

    Returns number

    The UTC last-updated timestamp.

  • set lastUpdatedAtU(value: number): void

  • Sets the UTC last-updated timestamp for this index.

    Parameters

    • value: number

      The new UTC timestamp value.

    Returns void

layerNames

objectId

  • get objectId(): string

  • Gets the object ID.

    AutoCAD uses 64-bit integers to represent handles, which exceed the maximum integer value of JavaScript. Therefore, strings are used to represent object handles.

    Returns string

    The object ID as a string

    Example

    const id = obj.objectId;
    console.log(`Object ID: ${id}`);
  • set objectId(value: string): void

  • Sets the object ID.

    Parameters

    • value: string

      The new object ID

    Returns void

    Example

    obj.objectId = 'new-object-id';

ownerId

  • get ownerId(): string

  • Gets the object ID of the owner of this object.

    Returns string

    The owner object ID

    Example

    const ownerId = obj.ownerId;
  • set ownerId(value: string): void

  • Sets the object ID of the owner of this object.

    Parameters

    • value: string

      The new owner object ID

    Returns void

    Example

    obj.ownerId = 'parent-object-id';

Methods

ProtectedassignDatabase

clone

clonePreservingIdentity

close

  • close(): void

  • Closes the object.

    All changes made to the object since it was opened are committed to the database, and a "closed" notification is sent. This method can be overridden by subclasses to provide specific cleanup behavior.

    Returns void

    Example

    obj.close();

compute

  • compute(
        layerTable?: AcDbLayerTable,
        blockTableRecord?: AcDbBlockTableRecord,
    ): boolean

  • Computes (rebuilds) this layer index from a layer table and block table record.

    Parameters

    Returns boolean

    true if the compute succeeded.

    Remarks

    Mirrors ObjectARX AcDbLayerIndex::compute. This port records layer names present in layerTable and associates the index with blockTableRecord; IDBUFFER population is not performed here.

createExtensionDictionary

  • createExtensionDictionary(): undefined | string

  • Creates the extension dictionary for this object if it does not already exist.

    This method closely mirrors the behavior of AcDbObject::createExtensionDictionary() in ObjectARX.

    • If the object already owns an extension dictionary, no new dictionary is created and the existing dictionary's objectId is returned.
    • Otherwise, a new AcDbDictionary is created, added to the same database, owned by this object, and its objectId is stored on this object.

    Returns undefined | string

    The objectId of the extension dictionary

    Example

    const dictId = obj.createExtensionDictionary()

dxfIn

  • dxfIn(filer: AcDbDxfFiler): this

  • Reads this object from a DXF filer (ObjectARX dxfIn).

    Reads common handle/owner fields, then delegates to dxfInFields. XData (group 1001+) is consumed when present after object fields.

    Group-102 control strings ({ACAD_XDICTIONARY, {ACAD_REACTORS, …) are consumed here so subclass readers still see handle/owner/subclass markers that follow them. Many real DXF writers emit these blocks on LAYER and entity records; skipping them would leave name/layer unset.

    Parameters

    Returns this

ProtecteddxfInControlString

dxfInFields

  • dxfInFields(filer: AcDbDxfFiler): this

  • Reads object-specific DXF fields (ObjectARX dxfInFields).

    Subclasses should override, call super.dxfInFields(filer) first when appropriate, then consume their subclass marker and fields in an order-independent loop.

    Per the AutoCAD DXF specification, readers must ignore undefined group codes and must not assume field order. Within a subclass loop the correct unknown-code behavior is break (skip and continue). Use pushBackItem only to hand a group-100 subclass marker (or XData) to another reader — never to abort on an unrecognized optional code.

    Parameters

    Returns this

ProtecteddxfInXData

dxfOut

dxfOutFields

ProtecteddxfOutXData

getAttr

  • getAttr(attrName: string): any

  • Gets the value of the specified attribute.

    This method will throw an exception if the specified attribute doesn't exist. Use getAttrWithoutException() if you want to handle missing attributes gracefully.

    Parameters

    • attrName: string

      The name of the attribute to retrieve

    Returns any

    The value of the specified attribute

    Throws

    When the specified attribute doesn't exist

    Example

    try {
      const value = obj.getAttr('objectId');
    } catch (error) {
      console.error('Attribute not found');
    }

getAttrWithoutException

  • getAttrWithoutException(attrName: string): any

  • Gets the value of the specified attribute without throwing an exception.

    This method returns undefined if the specified attribute doesn't exist, making it safer for optional attributes.

    Parameters

    • attrName: string

      The name of the attribute to retrieve

    Returns any

    The value of the specified attribute, or undefined if it doesn't exist

    Example

    const value = obj.getAttrWithoutException('optionalAttribute');
    if (value !== undefined) {
      // Use the value
    }

getXData

  • getXData(appId: string): undefined | AcDbResultBuffer

  • Retrieves the XData associated with this object for a given application ID.

    Extended Entity Data (XData) allows applications to attach arbitrary, application-specific data to an AcDbObject. Each XData entry is identified by a registered application name (AppId) and stored as an AcDbResultBuffer.

    This method is conceptually equivalent to AcDbObject::xData() in ObjectARX, but simplified to return the entire result buffer for the specified AppId.

    Parameters

    • appId: string

      The application ID (registered AppId name) that owns the XData

    Returns undefined | AcDbResultBuffer

    The AcDbResultBuffer associated with the AppId, or undefined if no XData exists for that AppId

    Example

    const xdata = obj.getXData('MY_APP')
    if (xdata) {
      // Read values from the result buffer
    }

newIterator

objectBeingIndexedId

rebuildFull

ProtectedrebuildModified

  • rebuildModified(_changeIterator?: object): boolean

  • Incrementally rebuilds this layer index for modified block contents.

    Parameters

    • Optional_changeIterator: object

      Optional iterator over changed block entities.

    Returns boolean

    true if the rebuild succeeded.

    Remarks

    Mirrors ObjectARX AcDbLayerIndex::rebuildModified.

removeXData

  • removeXData(appId: string): void

  • Removes the XData associated with the specified application ID.

    After removal, calls to getXData() for the same AppId will return undefined. If no XData exists for the given AppId, this method has no effect.

    This mirrors the behavior of clearing XData for a specific application in ObjectARX rather than removing all XData from the object.

    Parameters

    • appId: string

      The application ID whose XData should be removed

    Returns void

    Example

    obj.removeXData('MY_APP')

restoreFrom

setAttr

setObjectBeingIndexedId

setXData

  • setXData(resbuf: AcDbResultBuffer): void

  • Attaches or replaces XData for this object.

    If XData already exists for the given AppId, it is replaced by the provided AcDbResultBuffer. The caller is responsible for ensuring that:

    • The AppId is registered in the database's AppId table
    • The result buffer follows valid DXF/XData conventions (e.g. starts with a 1001 group code for the AppId)

    This method is conceptually similar to AcDbObject::setXData() in ObjectARX.

    Parameters

    Returns void

    Example

    const rb = new AcDbResultBuffer([
      { code: AcDbDxfCode.ExtendedDataRegAppName, value: 'MY_APP' },
      { code: AcDbDxfCode.ExtendedDataAsciiString, value: 'custom value' }
    ])

    obj.setXData('MY_APP', rb)

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